@media only screen and (max-width:992px)
{
    body
    {
        width:100%;
        background-image:none;
        background-color:white;
        background-size:100%;
        left:0;
        top:0;
    }
    .leftColumn,
    .rightColumn
    {
        display:none;
    }
    .centerColumn
    {
        width:100%;
        margin:0;
        border:none;
        box-shadow:none;
    }
    .listDocs
    {
        width:100%;
        box-shadow:none;
    }
    #listBills,
    #addPayment
    {
        width:97%;
    }
}